Abstract: Carbon monoxide — from toxicity to therapeutic potential: Carbon monoxide (CO) has long been known as a toxic gas, primarily associated with environmental pollution and poisoning. Its strong affinity for hemoglobin causes the formation of carboxyhemoglobin, which reduces oxygen delivery to the tissues and organs and leads to hypoxia. Despite its well-documented toxicity, previous studies have confirmed that CO also acts as a signaling molecule in the body and plays important physiological roles (Motterlini and Otterbein, 2010). This dual nature, both harmful and potentially beneficial, has led to studies of controlled CO exposure in the treatment of central nervous system (CNS) injuries.